Removal composition for selectively removing hard mask and methods thereof

ABSTRACT

The present disclosure relates to a removal composition for selectively removing an hard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti and alloys of Ti and W relative to low-k dielectric material from a semiconductor substrate. The semiconductor substrate comprises a low-k dielectric material having a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard mask thereon. The removal composition comprises 0.1 wt % to 90 wt % of an oxidizing agent; 0.0001 wt % to 50 wt % of a carboxylate; and the balance up to 100 wt % of the removal composition comprising deionized water.

CROSS REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCESTATEMENT

This application claims the benefit of U.S. provisional application Ser.No. 61/889,968, filed Oct. 11, 2013, the entire contents of which arehereby incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

The presently disclosed and claimed inventive concept(s) relates tocompositions and methods for selectively removing hard mask and otherresidues from integrated circuit (IC) device substrates, and, moreparticularly, to compositions and methods useful for selectivelyremoving TiN, TaN, TiNxOy, TiW, Ti and W hard mask, and hard maskscomprising alloys of the foregoing, as well as other residues from suchsubstrates comprising low-k dielectric materials, TEOS, copper, cobaltand other low-k dielectric materials, using a carboxylate compound.

Plasma dry etching is commonly used to fabricate vertical sidewalltrenches and anisotropic interconnecting vias in copper (Cu)/low-k dualdamascene fabrication processes. As the technology nodes advance to 45nm and smaller, the decreasing size of the semiconductor devices makesachieving critical profile control of vias and trenches morechallenging. Integrated circuit device companies are investigating theuse of a variety of hard masks to improve etch selectivity to low-kmaterials and thereby gain better profile control.

In order to obtain high yield and low resistance, polymer residues onthe sidewalls and the particulate/polymer residues at the via bottomsthat are generated during etching must be removed prior to the nextprocess step. It would be very beneficial if the removal composition(cleaning solution) can also effectively etch the hard mask to form anintermediate morphology, e.g., a pulled-back/rounded morphology, orcompletely remove the hard mask. A pulled-back/rounded morphology couldprevent undercutting the hard mask, which, in turn, could enablereliable deposition of barrier metal, Cu seed layer and Cu filling.Alternatively, fully removing the hard mask using the same compositioncould offer numerous benefits to downstream process steps, particularlychemical mechanical polishing (CMP), by eliminating a need for barrierCMP.

Following almost every step in the fabrication process, e.g., aplanarization step, a photolithography step, or an etching step, removal(cleaning) processes are required to remove residues of the plasma etch,photoresist, oxidizer, abrasive, metal and/or other liquids or particlesthat remain and which can contaminate the surface of the device if theyare not effectively removed. Fabrication of advanced generation devicesthat require copper conductors and low-k dielectric materials (typicallycarbon-doped silicon oxide (SiOCH), or porous low-k materials) give riseto the problem that both materials can react with and be damaged byvarious classes of prior art cleaners.

Low-k dielectrics, in particular, may be damaged in the removal processas evidenced by etching, changes in porosity/size, and ultimatelychanges in dielectric properties. Time required to remove residuesdepends on the nature of the residue, the process (heating,crosslinking, etching, baking, and/or ashing) by which it was created,and whether batch or single wafer removal processes can be used. Someresidues may be cleaned in a very short period of time, while someresidues require much longer removal procedures. Compatibility with boththe low-k dielectric and with the copper conductor over the duration ofcontact with the removal composition is a desired characteristic.

During back-end-of-line (BEOL) IC fabrication processes, i.e., dualdamascene processes, TiN, TaN, TiNxOy, TiW, Ti, and/or W (includingalloys of Ti and W) are used as an hard mask in the formation of viasand trenches to gain high selectivity to low-k dielectric materialsduring dry etching steps. Effective removal compositions are requiredthat can selectively remove the TiN, TaN, TiNxOy, TiW, Ti or W, becompatible with low-k materials, copper, cobalt and other dielectricmaterials, and also simultaneously remove unwanted etching residues andCu oxide from the resulting dual damascene structure. Beyond selectiveremoval, it is also highly desirable that the achievable removal rate ofa hard mask (Å/min) for the removal composition be maintainedsubstantially constant for an extended period of time.

With the continuing reduction in device critical dimensions andcorresponding requirements for high production efficiency and reliabledevice performance, there is a need for such improved removalcompositions.

SUMMARY

The present disclosure relates to an improved semiconductor processingcomposition, i.e., a wet cleaning chemistry or removal composition, withone or more carboxylates which provides highly selective removal of hardmask from a dual damascene structure without damaging wiring metallurgyand dielectric materials. Semiconductor substrates of the typefabricated in dual damascene back end metallization consist of multiplelayers or levels of metal interconnects that are isolated by interlayerdielectrics (Low-k dielectric material). The removal composition canremove hard mask etch residues, photoresist, polymeric materials, andcopper oxide from via and trench surfaces without damaging underlyinglayers that form the structure. The semiconductor substrates typicallycomprise copper, cobalt, a Low-k dielectric material(s), SiON, SiCN,TEOS and a hard mask selected from TiN, TaN, TiNxOy, TiW, W, Ti,including alloys of Ti and W. The removal composition comprises 0.1 wt %to 90 wt % at least one oxidizing agent, 0.0001 wt % to 50 wt % of acarboxylate, with the balance up to 100 wt % of the removal compositioncomprising water, e.g., deionized water.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are cross-sectional SEM images of semiconductor wafersegments which show trenches and vias, respectively, during dualdamascene device fabrication, but prior to contact with the removalcomposition of the invention.

FIGS. 2A and 2B are cross-sectional SEM images of semiconductor wafersegments of the type shown in FIGS. 1A and 1B after contact with removalcomposition 1 from Table 1 at 50° C. for 90 sec.

FIGS. 3A and 3B are cross-sectional SEM images of semiconductor wafersegments of the type shown in FIGS. 1A and 1B after contact with removalcomposition 2 from Table 1 at 50° C. for 90 sec.

FIGS. 4A and 4B are cross-sectional SEM images of semiconductor wafersegments of the type shown in FIGS. 1A and 1B after contact with removalcomposition 3 from Table 1 at 53° Detailed C for 90 sec.

DETAILED DESCRIPTION

It is recognized that various components of the compositions of thisinvention may interact, and, therefore, any composition is expressed asthe amount of various components which, when added together, form thecomposition. Unless specifically stated otherwise, any composition givenin percent is percent by weight (wt %) of that component that has beenadded to the composition. When the composition is described as beingsubstantially free of a particular component, generally there arenumeric ranges provided to guide one of ordinary skill in the art towhat is meant by “substantially free,” but in all cases “substantiallyfree” encompasses the preferred embodiment where the composition istotally free of that particular component.

As noted briefly above, the dual damascene process is used to form metalinterconnects in the backend metallization, which are then used toelectrically interconnect various electrical components in asemiconductor substrate into functional circuits. A discussion ofbackend metallization, which comprises fabrication of multiple levels,or layers, of metal interconnects isolated by an interlayer dielectriclayer(s) and/or barrier layer(s) can be found, for example, in U.S. Pat.No. 8,080,475, the teachings of which are incorporated herein in theirentirety by reference. The integration of new materials, such as ultralow-k dielectrics, into microelectronic devices places new demands onremoval performance. Concurrently, shrinking device dimensions reducesthe tolerances for changes in critical dimensions for vias and trenches.

The described and claimed inventive concept(s) reside in the discoverythat selective removal of hard mask from semiconductor substrate whereinsaid hard mask is in overlapping relationship with a low-k dielectricmaterial can be accomplished by incorporating into the removalcomposition an effective amount of from 0.0001 wt % up to 50 wt % of acarboxylate. In a preferred embodiment, the concentration of carboxylateis from 0.001 wt % up to 10 wt %. Another advantage is the addition of acarboxylate increases the etch rate of a hard mask selected from TiN,TaN, TiNxOy, TiW, W, Ti, including alloys of Ti and W.

Yet another advantage resides in the discovery that ammoniumcarboxylates in combination with CDTA in removal composition of thepresent disclosure increase etch rate as well as stabilize the etchrate. And yet another advantage resides in the discovery that ammoniumethylenediaminetetraacetic acids not only increase the etch rate butalso stabilize the etch rate.

The chemicals in a removal composition for removing a metal hard maskcan decompose over time. The term “stabilize” or “stabilized” is usedherein to mean that the achievable etch rate for a hard mask remainssubstantially constant over an extended period of time, e.g., a timeperiod of from twenty two (22) hours and up to thirty five (35) hours orlonger at the selected operating temperature. For example, the etch rateof the removal composition after for 2, 4, or 8 hrs of use issubstantially the same after 20, 24 or 35 hrs of use.

The term “substantially constant” is intended to mean that decompositionover time is minimized or less than if ammoniumethylenediaminetetraacetic acids or a combination of ammoniumcarboxylate(s) and amino acid, amine polycarboxylic acid, carboxylicacid or polycarboxylic acid chelating agent were not used in the removalcomposition. Thus, the etch rate does not decrease as much as whenammonium ethylenediaminetetraacetic acids or a combination of ammoniumcarboxylate(s) and amino acid, amine polycarboxylic acid, carboxylicacid or polycarboxylic acid chelating agent were not used.

The term “selectively removing” is intended to mean removing the hardmask without damaging the underlying metal conductor layer (metalinterconnect) and Low-k dielectric material. Low-k dielectric materialis any material used as a dielectric material in a semiconductorsubstrate or any microelectronic device where in the dielectric constantis less than 3.5. Examples of useful Low-k dielectric materials includebut are not limited to: silicon dioxide (SiO₂), carbon-doped siliconoxide (SiOCH), low-polarity materials such as organic polymers, hybridorganic, inorganic materials, organosilicate glass (OSG), andcarbon-doped oxide (CDO) glass. The incorporation of porosity, i.e.air-filled pores, in these materials further lowers the dielectricconstant of the material.

Carboxylate

The term “carboxylate” is used herein to mean the general formulaM(RCOO)n, where M is a metal and n is 1, 2, . . . is the number ofcarboxylate esters within the compound having the general formulaRCOOR′, wherein R and R′ are organic groups with the proviso that R′≠H.When chemistries of the type described herein are used in electronicdevice fabrication, such as fabricating IC devices, it is preferable notto have any metal impurities in the chemical composition. In such cases,M is replaced with NH4+. The removal composition of the presentdisclosure selectively removes a hard mask from a semiconductorsubstrate. The hard mask consists essentially of TiN, TaN, TiNxOy, TiW,W, Ti and alloys of Ti and W. The removal composition selectivelyremoves the hard mask relative to the low-k dielectric material of asemiconductor substrate. The removal composition comprises:

(a) from 0.1 wt % to 90 wt % of an oxidizing agent;

(b) from 0.0001 wt % to 50 wt % of a carboxylate; and

(c) the balance up to 100 wt % of the removal composition comprisingdeionized water.

The presence of a carboxylate in the removal composition increases theetch rate of a metal hard mark at least 8% when compared to the sameremoval composition with out a carboxylate and in some embodiments, atleast 39% or 43% or 50% or 60% or 75 or 80%. In some embodiments, thecarboxylate is selected from the group consisting of potassium citratetribasic monohydrate, potassium sodium tartrate tetrahydrate, potassiumL-Lactate and mixtures thereof.

In some embodiments, the carboxylate is an ammonium carboxylate. In someembodiments, the ammonium carboxylate is selected from the groupconsisting of ammonium oxalate, ammonium lactate, ammonium tartrate.ammonium citrate tribasic, ammonium acetate, ammonium carbamate,ammonium carbonate, ammonium benzoate, ammoniumethylenediaminetetraacetic acid, diammonium ethylenediaminetetraaceticacid, triammonium ethylenediaminetetraacetic acid, tetraammoniumethylenediaminetetraacetic acid, ammonium succinate, ammonium formate,ammonium 1-H-pyrazole-3-carboxylate and mixtures thereof.

The carboxylate is present in an amount from 0.0001 wt % to 50 wt %based on the total weight of the removal composition. In someembodiments, the carboxylate is present in an amount from 0.0001 wt % to25 wt % based on the total weight of the removal composition. In someembodiments, the carboxylate is present in an amount from 0.0001 wt % to10 wt % based on the total weight of the removal composition. In anotherembodiment, the carboxylate is present in an amount from 0.0001 wt % to0.6 wt % based on the total weight of the removal composition. Inanother embodiment, the carboxylate is present in an amount from 0.001wt % to 50 wt % based on the total weight of the removal composition. Inanother embodiment, the carboxylate is present in an amount from 0.001wt % to 10 wt % based on the total weight of the removal composition. Inyet another embodiment, the carboxylate is present in an amount from 0.2to 0.5 wt % based on the total weight of the removal composition

In yet another embodiment, the ammonium carboxylate is present in anamount from 0.0001 wt % to 50 wt % based on the total weight of theremoval composition. In some embodiments, the ammonium carboxylate ispresent in an amount from 0.0001 wt % to 25 wt % based on the totalweight of the removal composition. In some embodiments, the ammoniumcarboxylate is present in an amount from 0.0001 wt % to 10 wt % based onthe total weight of the removal composition. In another embodiment, theammonium carboxylate is present in an amount from 0.0001 to 0.6 wt %based on the total weight of the removal composition. In yet anotherembodiment, the ammonium carboxylate is present in an amount from 0.001wt % to 50 wt % based on the total weight of the removal composition. Inanother embodiment, the ammonium carboxylate is present in an amountfrom 0.001 wt % to 10 wt % based on the total weight of the removalcomposition. In yet another embodiment, the ammonium carboxylate ispresent in an amount from 0.2 to 0.5 wt % based on the total weight ofthe removal composition

In some embodiments, the ammonium carboxylate is an ammoniumethylenediaminetetraacetic acid or mixture thereof. The presence ofammonium ethylenediaminetetraacetic acids in the removal compositions ofthis disclosure not only increased the etch rate of the hard mask butalso operates to stabilize the achievable etch rate over an extendedperiod of time (up to at least 22 hours and in some embodiments up to atleast 35 hours).

In some embodiments, the ammonium ethylenediaminetetraacetic acids areselected from the group consisting of ammoniumethylenediaminetetraacetic acid, diammonium ethylenediaminetetraaceticacid, triammonium ethylenediaminetetraacetic acid, tetraammoniumethylenediaminetetraacetic acid and mixtures thereof.

In one embodiment, ammonium ethylenediaminetetraacetic acids stabilizeetch rate. In some embodiments, ammonium ethylenediaminetetraaceticacids stabilize TiN etch rate. In some embodiments, ammoniumethylenediaminetetraacetic acids stabilize TiN etch rate such that TiNetch rate at 50° C. does not drop more than 20% or 45 Å/min at 35 hours.The etch rate at 50° C. of a removal composition without the addition ofan ammonium ethylenediaminetetraacetic acid, drops 60% or 86 Å/min at 35hours.

In some embodiments, the ammonium carboxylate is tetraammoniumethylenediaminetetraacetic acid. In some embodiments, tetraammoniumethylenediaminetetraacetic acid stabilizes the TiN etch rate such thatTiN etch rate at 50° C. which does not drop more than 20% or 45 Å/min at35 hours. For a removal composition without tetraammoniumethylenediaminetetraacetic acid, the TiN etch rate at 50° C. drops 60%or 86 Å/min at 35 hours.

Oxidizing Agent

Oxidizing agents useful according to the inventive concept(s) areselected from any substance which has the capability to chemically reactwith the hard mask and effect its removal. The removal compositionoxidizing agent is selected from the group consisting of hydrogenperoxide (H2O2), n-methylmorpholine oxide (NMMO or NMO), benzoylperoxide, tetrabutylammonium peroxymonosulfate, ozone, ferric chloride,permanganate peroxoborate, perchlorate, persulfate, ammoniumperoxydisulfate, per acetic acid, urea hydroperoxide, nitric acid(HNO3), ammonium chlorite (NH4ClO2), ammonium chlorate (NH4ClO3),ammonium iodate (NH4IO3), ammonium perborate (NH4BO3), ammoniumperchlorate (NH4ClO4), ammonium periodate (NH4IO3), ammonium persulfate((NH4)2S2O8), tetramethylammonium chlorite ((N(CH3)4)ClO2),tetramethylammionium chlorate ((N(CH3)4)ClO3), tetramethylammoniumiodate ((N(CH3)4)IO3), tetramethylammonium perborate ((N(CH3)4)BO3),tetramethylammonium perchlorate ((N(CH3)4)ClO4), tetramethylammoniumperiodate ((N(CH3)4)IO4), tetramethylammonium persulfate((N(CH3)4)S2O8), ((CO(NH2)2)H2O2), peracetic acid (CH3(CO)OOH), andmixtures thereof. Among the foregoing, H2O2 is a most preferredoxidizing agent being low concentration of metals and providing ease ofhandling and lower relative cost.

In one embodiment, the removal composition comprises from 0.1 wt % to 90wt % of an oxidizing agent. In another embodiment, the removalcomposition comprises from 0.1 wt % to 24 wt % of an oxidizing agent. Inanother embodiment, the removal composition comprises from 3 wt % to 24wt % of an oxidizing agent.

Acids/Chelating Agents

The removal composition may also include an amino acid, aminepolycarboxylic acid (i.e., aminopolycarboxylic acid), and/or carboxylicacid, polycarboxylic acid chelating agent, or a mixture thereof. Thepresence of an amino acid, amine polycarboxylic acid (i.e.,aminopolycarboxylic acid), and/or carboxylic acid, polycarboxylic acidchelating agent, or a mixture thereof in combination with an ammoniumcarboxylate or mixtures of ammonium carboxylates, was observed tostabilize the etch rate up to at least 22 hours or even up to 35 hours.

In some embodiments, the removal composition includes 0.0005 wt % to 20wt % of an amino acid, amine polycarboxylic acid (i.e.,aminopolycarboxylic acid), and/or carboxylic acid, polycarboxylic acidchelating agent, or a mixture thereof. In some embodiments, the removalcomposition includes 0.001 wt % to 20 wt % of an amino acid, aminepolycarboxylic acid (i.e., aminopolycarboxylic acid), and/or carboxylicacid, polycarboxylic acid chelating agent, or a mixture thereof. Inanother embodiment, the removal composition includes 0.001 wt % to 10 wt% of an amino acid, amine polycarboxylic acid (i.e., aminopolycarboxylicacid), and/or carboxylic acid, polycarboxylic acid chelating agent, or amixture thereof. In another embodiment, the removal composition includes0.001 wt % to 5 wt % of an amino acid, amine polycarboxylic acid (i.e.,aminopolycarboxylic acid), and/or carboxylic acid, polycarboxylic acidchelating agent, or a mixture thereof. In another embodiment, theremoval composition includes 0.001 wt % to 1 wt % of an amino acid,amine polycarboxylic acid (i.e., aminopolycarboxylic acid), and/orcarboxylic acid, polycarboxylic acid chelating agent, or a mixturethereof. In another embodiment, the removal composition includes 0.001wt % to 0.607 wt % of an amino acid, amine polycarboxylic acid (i.e.,aminopolycarboxylic acid), and/or carboxylic acid, polycarboxylic acidchelating agent, or a mixture thereof.

Examples of such chelating agents include, but are not limited to,1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA);ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid (DOCTA); andtriethylenetetraamine hexaacetic acid (TTNA).

The addition of 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid to aremoval composition having an ammonium carboxylate stabilizes the TiNetch rate up to at least 35 hrs. The etch rate at 50° C. of a removalcomposition having ammonium carboxylate without1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid may decrease 48% oreven 54% after 35 hours. Whereas if 0.2 to 0.8 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid is added the theammonium carboxylate removal composition TiN etch rate at 50° C.decreases 8% or less and in one embodiment decreases 0.4%. Whenstability of a removal composition having an ammonium carboxylate isimportant, 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid can beadded to the removal composition. The amount of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid can be tailored toachieve the desired stability.

In one embodiment, 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid ispresent in an amount from 0.0005 to 20 wt % based on the total weightpercent of the removal composition. In one embodiment,1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid is present in anamount from 0.0005 to 10 wt % based on the total weight percent of theremoval composition. In one embodiment,1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid is present in anamount from 0.001 to 10 wt % based on the total weight percent of theremoval composition. In another embodiment,1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid is present in anamount from 0.001 to 5 wt %. In another embodiment,1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid is present in anamount from 0.001 to 1 wt %. In another embodiment,1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid is present in anamount from 0.001 wt % to 0.607 wt %.

In some embodiments, a removal composition comprising

(a) 0.1 wt % to 90 wt % at least one oxidizing agent,

(b) 0.0001 wt % to 50 wt % of an ammonium carboxylate;

(c) 0.001 wt % to 20 wt % of an amino acid, an aminopolycarboxylic acid,a carboxylic acid, a polycarboxylic acid, or a mixture thereof selectedfrom the group consisting of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);and ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid; and triethylenetetraaminehexaacetic acid (TTNA); and(d) the balance up to 100 wt % of the removal composition comprisingdeionized water stabilize the etch rate up to at least 35 hours. In someembodiments, stabilize TiN etch rate up to at least 35 hours. And insome embodiments, stabilize TiN etch rateup to at least 35 hours at aselected operating temperature. In some embodiments, the selectedoperating temperature is from 20 to 60° C. In another embodiment, theselected operating temperature is between and including any two of thefollowing temperature: 20, 30, 45, 50, 53 and 60° C.

In some embodiments, the addition of a chelating agent stabilizes theTiN etch rate such that TiN etch rate at 50° C. does not drop more than23 Å/min at 24 hours. In some embodiments, the addition of a chelatingagent stabilizes the TiN etch rate such that TiN hard mask etch rate at50° C. does not drop more than 22.5 Å/min at 24 hours. In someembodiments, the addition of a chelating agent stabilizes the TiN etchrate such that TiN etch rate at 50° C. does not drop more than 20.5Å/min at 24 hours. In some embodiments, the addition of a chelatingagent stabilizes the TiN etch rate such that TiN etch rate at 50° C.does not drop more than 11 Å/min at 24 hours.

Metal Corrosion Inhibitor

Although not required for carrying out the invention, at least onecorrosion inhibitor may also be present in the removal composition, forexample, where the removal composition is to be deployed insemiconductor processing at BEOL applications and other applicationswhere corrosion of copper or other metal components is a concern. Thepresence of a corrosion inhibitor is needed to protect metal surfacesfrom being etched or otherwise degraded. For other applications,including FEOL applications, of the inventive composition and associatedmethod, a corrosion inhibitor(s) is not generally needed, i.e., copperor cobalt, is not exposed to the removal chemistry, copper or cobalt isabsent from the wafer substrate, or slight etching/degradation of copperor cobalt surfaces is not usually a concern.

The metal (copper or cobalt) corrosion inhibitor is an organic compound,such as an azole, thiol, and/or indole preferably selected from thegroup consisting of a heterocyclic compound containing at least onenitrogen atom, such as, for example, a pyrrole and derivatives thereof,pyrazole and derivatives thereof, imidazole and derivatives thereof,triazole and derivatives thereof, indazole and derivatives thereof, andthiol-triazole and derivatives thereof, benzotriazole (BTA),tolyltriazole, 5-phenyl-benzotriazole, 5-nitro-benzotriazole,3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole,hydroxybenzotriazole, 2-(5-amino-pentyl)-benzotriazole,1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole,3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole,3-isopropyl-1,2,4-triazole, 5-phenylthiol-benzotriazole,halo-benzotriazoles (halo=F, Cl, Br or I), naphthotriazole,2-mercaptobenzimidazole (MBI), 2-mercaptobenzothiazole,4-methyl-2-phenylimidazole, 2-mercaptothiazoline, 5-aminotetrazole,5-aminotetrazole monohydrate, 5-amino-1,3,4-thiadiazole-2-thiol,2,4-diamino-6-methyl-1,3,5-triazine, thiazole, triazine,methyltetrazole, 1,3-dimethyl-2-imidazolidinone,1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole,diaminomethyltriazine, imidazoline thione, mercaptobenzimidazole,4-methyl-4H-1,2,4-triazole-3-thiol, 5-amino-1,3,4-thiadiazole-2-thiol,benzothiazole, and mixtures thereof. Among the foregoing, benzotriazole,pyrazole, or a mixture of benzotriazole and pyrazole, or a mixture ofbenzotriazole and tolyltriazole (available commercially from Wincom,Inc. under the name “Wintrol A-90”), are preferred copper corrosioninhibitors for better removal performance.

The copper or cobalt corrosion inhibitor or mixture thereof may bepresent in the composition at from 0.0001 wt % to 50 wt %. In anotherembodiments, the copper or cobalt corrosion inhibitor or mixture thereofis present in an amount from 0.0001 wt % to 10 wt %. In someembodiments, the copper or cobalt corrosion inhibitor or mixture thereofis present in an amount from 0.5 to 0.9 wt %. I In some embodiments, thecopper or cobalt corrosion inhibitor or mixture thereof is present in anamount from 0.18 to 0.8 wt %. In another embodiment, the copper orcobalt corrosion inhibitor or mixture thereof is present in an amountfrom 0.18 to 0.65 wt %. Other suitable copper or cobalt corrosioninhibitors include, but are not limited to aromatic hydrazides andSchiff base compounds.

In some embodiments, the composition can contain one or more cosolventsthat are miscible with water. Cosolvents enhance residue removal.Suitable cosolvents include, but are not limited to, sulfolane,N-methylpyrrolidone, and dimethylsulfoxide.

pH Adjustment

The composition may also include a base or an acid, as appropriate, toadjust the pH of the working composition. The base can, for example, beselected from the group consisting of quaternary ammonium salts, such astetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide(TEAH), benzyltrimethylammonium hydroxide (BTAH) and mixtures thereof.The base can also be selected from the group consisting of primary,secondary and tertiary amines, such as, for example, monoethanol amine(MEA), diglycol amine (DGA), triethanolamine (TEA), tetrabutyphosphoniumhydroxide (TBPH), and mixtures thereof. In some embodiments, the basecan be a combination of quaternary ammonium salts and amines. Suitableacids include, for example, are selected from the group consisting ofinorganic acids, such as sulfuric acid, nitric acid, phosphoric acid,hydrofluoric acid (HF), or hydrobromic acid; organic acids, such as acarboxylic acid, an amino acid, a hydroxy carboxylic acid, apolycarboxylic acid, or a mixture of such acids. The pH of the workingcomposition should be maintained at a value of from 2 to 14, butpreferably in the range of from 3 to 12. As noted above, when used inBEOL Cu interconnect fabrication applications, the preferred pH of theworking composition is in the range of from 5 to 11 when hydrogenperoxide is used as oxidizer in order to achieve high etch rates.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) 0.0005 wt % to 20 wt % of an amino acid, amine polycarboxylic acid(i.e., aminopolycarboxylic acid), and/or carboxylic acid, polycarboxylicacid chelating agent, or a mixture thereof; and

(d) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) 0.0005 wt % to 20 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid; and

(d) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(d) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixture ofmetal corrosion inhibitors; and

(d) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) 0.0005 wt % to 20 wt % of an amino acid, amine polycarboxylic acid(i.e., aminopolycarboxylic acid), and/or carboxylic acid, polycarboxylicacid chelating agent, or a mixture thereof;

(d) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(e) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) 0.0005 wt % to 20 wt % of an amino acid, amine polycarboxylic acid(i.e., aminopolycarboxylic acid), and/or carboxylic acid, polycarboxylicacid chelating agent, or a mixture thereof;

(d) 0.0001 to 50 wt % of a metal corrosion inhibitor;

(e) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(f) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) 0.0005 wt % to 20 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;

(d) 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixture ofmetal corrosion inhibitors; and

(e) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) 0.0005 wt % to 20 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;

(d) 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixture ofmetal corrosion inhibitors;

(e) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(f) the balance up to 100 wt % of the removal composition comprisingdeionized water.

And further, the removal composition in accordance with any of the aboveembodiments, wherein the carboxylate is an ammonium carboxylate. Theammonium carboxylate is selected from the group consisting of ammoniumoxalate, ammonium lactate, ammonium tartrate. ammonium citrate tribasic,ammonium acetate, ammonium carbamate, ammonium carbonate, ammoniumbenzoate, ammonium ethylenediaminetetraacetic acid, diammoniumethylenediaminetetraacetic acid, triammonium ethylenediaminetetraaceticacid, tetraammonium ethylenediaminetetraacetic acid, ammonium succinate,ammonium formate, ammonium 1-H-pyrazole-3-carboxylate and mixturesthereof

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of an ammonium carboxylate;

(c) 0.0005 wt % to 20 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;

(d) 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixture ofmetal corrosion inhibitors;

(e) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(f) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of an ammonium tartrate;

(c) 0.0005 wt % to 20 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA);

(d) 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixture ofmetal corrosion inhibitors;

(e) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(f) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of hydrogen peroxide;

(b) 0.0001 wt % to 50 wt % of an ammonium carboxylate; and

(c) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of hydrogen peroxide;

(b) 0.0001 wt % to 50 wt % of an ammonium carboxylate;

(c) 0.0005 wt % to 20 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid; and

(d) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of hydrogen peroxide;

(b) 0.0001 wt % to 50 wt % of an ammonium carboxylate;

(c) 0.0005 wt % to 20 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;

(d) from 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixtureof metal corrosion inhibitors; and

(e) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of an ammonium ethylenediaminetetraaceticacid;

(c) 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixture ofmetal corrosion inhibitors;

(d) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(e) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of tetraammonium ethylenediaminetetraaceticacid;

(c) 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixture ofmetal corrosion inhibitors;

(d) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(e) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In one embodiment, the removal composition for selectively removing anhard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising:

(a) 0.1 wt % to 90 wt % of an oxidizing agent;

(b) 0.0001 wt % to 50 wt % of tetraammonium ethylenediaminetetraaceticacid;

(c) 0.0005 wt % to 20 wt % of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;

(d) 0.0001 to 50 wt % of a metal corrosion inhibitor or a mixture ofmetal corrosion inhibitors;

(e) a base and mixtures thereof; or an acid and mixtures thereof; or amixture of base and acid; and

(f) the balance up to 100 wt % of the removal composition comprisingdeionized water.

Kit

Another embodiment of the present disclosure is a kit including one ormore containers comprising one or more components adapted to form theremoval composition. In some embodiments the kit includes in one or morecontainers, comprising at least one carboxylate and deionized water forcombining with an oxidizing agent at the point or fabrication or thepoint of use. In another embodiment, the kit includes in one or morecontainers, comprising at least one carboxylate; deionized water; atleast one copper corrosion inhibitor; and optionally comprising a base,a acid or mixture thereof for adjusting the pH; and optionallycomprising at least one cosolvent for combining with an oxidizing agentat the point or fabrication or the point of use. In another embodiment,the kit includes in one or more containers, comprising at least onecarboxylate; deionized water; at least one amino acid, aminepolycarboxylic acid (i.e., aminopolycarboxylic acid), and/or carboxylicacid, polycarboxylic acid chelating agent; and optionally comprising abase, a acid or mixture thereof for adjusting the pH; and optionallycomprising at least one cosolvent for combining with an oxidizing agentat the point or fabrication or the point of use. In another embodiment,the kit includes in one or more containers, comprising at least onecarboxylate; deionized water; at least one copper corrosion inhibitor;at least one amino acid, amine polycarboxylic acid (i.e.,aminopolycarboxylic acid), and/or carboxylic acid, polycarboxylic acidchelating agent; optionally comprising a base, a acid or mixture thereoffor adjusting the pH; and optionally comprising at least one cosolventfor combining with an oxidizing agent at the point or fabrication or thepoint of use.

Method

Removal composition is applied in any suitable manner to thesemiconductor substrate. Contact or contacting the semiconductorsubstrate is intended to include spraying, dipping, using a pad orapplicator that has the removal composition absorbed thereon or anyother suitable manner of contacting the semiconductor substrate with aremoval composition.

In one embodiment, a method for selectively removing an hard maskconsisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti, including alloysof Ti or W, relative to underlying Low-k, Cu, Co, SiON, SICN, and TEOSmaterials from a semiconductor substrate having a TiN, TaN, TiNxOy, TiW,W, or Ti hard mask thereon, including an hard mask comprising alloys ofTi or W, wherein the method comprises contacting the semiconductorsubstrate with a removal composition comprising:

(a) 0.1 wt % to 90 wt % at least one oxidizing agent;

(b) 0.0001 wt % up to 50 wt % of a carboxylate; and

(c) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In some embodiments, the method for selectively removing an hard maskconsisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti, including alloysof Ti or W, relative to underlying Low-k, Cu, Co, SiON, SICN, and TEOSmaterials from a semiconductor substrate having a TiN, TaN, TiNxOy, TiW,W, or Ti hard mask thereon, including an hard mask comprising alloys ofTi or W, wherein the method comprises contacting the semiconductorsubstrate with a removal composition comprising:

(a) 0.1 wt % to 90 wt % at least one oxidizing agent;

(b) 0.0001 wt % up to 50 wt % of an ammonium carboxylate; and

(c) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In some embodiments, the method for selectively removing an hard maskconsisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti, including alloysof Ti or W, relative to underlying Low-k, Cu, Co, SiON, SICN, and TEOSmaterials from a semiconductor substrate having a TiN, TaN, TiNxOy, TiW,W, or Ti hard mask thereon, including an hard mask comprising alloys ofTi or W, wherein the method comprises contacting the semiconductorsubstrate with a removal composition comprising:

(a) from 0.1 wt % to 90 wt % at least one oxidizing agent;

(b) from 0.0001 wt % up to 50 wt % of an ammonium carboxylate selectedfrom the group consisting of ammonium oxalate, ammonium lactate,ammonium tartrate. ammonium citrate tribasic, ammonium acetate, ammoniumcarbamate, ammonium carbonate, ammonium benzoate, ammoniumethylenediaminetetraacetic acid, diammonium ethylenediaminetetraaceticacid, triammonium ethylenediaminetetraacetic acid, tetraammoniumethylenediaminetetraacetic acid, ammonium succinate, ammonium formate,ammonium 1-H-pyrazole-3-carboxylate and mixtures thereof; and

(c) the balance up to 100 wt % of the removal composition comprisingdeionized water.

In some embodiments in accordance with any of the above methods, theremoval composition may additionally comprise at least one metalcorrosion inhibitor. In some embodiments in accordance with any of theabove methods, the removal composition may additionally comprise from0.001 wt % to 20 wt % of an amino acid, an aminopolycarboxylic acid, acarboxylic acid, a polycarboxylic acid, or a mixture thereof selectedfrom the group consisting of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);and ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid (DOCTA); andtriethylenetetraamine hexaacetic acid (TTNA). In some embodiments inaccordance with any of the above methods, the removal composition mayadditionally comprise at least one base, at least one acid or mixturethereof; wherein the base is selected from the group consisting ofquaternary ammonium salts, primary amines, secondary amines, tertiaryamines; and wherein the acid is selected from the group consisting ofinorganic acids, organic acids or mixtures thereof.

In some embodiments in accordance with any of the above methods, theremoval composition may additionally comprise at least one base at leastone acid or mixture thereof, wherein the base is selected fromtetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide(TEAH), benzyltrimethylammonium hydroxide (BTAH), monoethanol amine(MEA), diglycol amine (DGA), triethanolamine (TEA), tetrabutyphosphoniumhydroxide (TBPH), and mixtures thereof and the acid is selected from thegroup consisting of inorganic acids, organic acids or mixtures thereof.

In some embodiments, the method for removing a hard mask consistingessentially of TiN, TaN, TiNxOy, TiW, W, Ti and alloys of Ti and W froma semiconductor substrate, the method comprising contacting thesemiconductor substrate with a removal composition comprising:

(a) 0.1 wt % to 90 wt % at least one oxidizing agent,

(b) 0.0001 wt % to 50 wt % of a carboxylate;

(c) the balance up to 100 wt % of the removal composition comprisingdeionized water

In some embodiments, the method additionally comprises the heating theremoval composition up to 60° C. Heating the removal composition canoccur prior to contacting the semiconductor substrate or after. In someembodiments, the method comprises contacting the semiconductor substratewith a removal composition for at least 2 minutes at a temperature from20 to 45, 50, 53 or 60° C. In some embodiments, the method comprisescontacting the semiconductor substrate with a removal composition for atleast 2 minutes at a temperature up to 60° C.

A composition formulated according to the present disclosure andexhibiting an inherently high etch rate for TiN, TaN, TiNxOy, TiW, W,Ti, including alloys of Ti and W, enables processing at relatively lowtemperature, e.g., temperatures less than 65° C. A relatively lowtemperature process exhibits a reduced oxidizer decomposition rate,which, in turn, extends the useful composition bath life and pot life.Additionally, compositions according to the invention which exhibit highand selective etch rates for TiN, TaN, TiNxOy, TiW, W, Ti, includingalloys of Ti and W, are desirable because they can reduce deviceprocessing time and thereby increase throughput. Typically, high etchrates for TiN, TaN, TiNxOy, TiW, W, Ti, including alloys of Ti and W,have been achieved by increasing process temperatures. However, forsingle wafer process applications, the highest processing temperature isaround 75° C., which, in turn, can limit the upper end of etch rates forTiN, and thereby limit the ability for one to completely remove TiN hardmask from a dual damascene structure. Compositions according to theinvention can effectively deliver high etch rates for TiN, TaN, TiNxOy,TiW, W, Ti, including alloys of Ti and W, with single wafer toolapplications at a temperature range of from 20° C. to 60° C., and theTiN, TaN, TiNxOy, TiW, W, Ti, including alloys of Ti and W, hard maskcan be fully removed with single wafer application process equipment ifso desired.

In some embodiments, the removal composition is at a temperature from 20to 45, 50, 53 or 60° C. and at a pH from 2 to 14. In some embodiments,the removal composition is at a temperature from 20 to 45, 50, 53 or 60°C. and at a pH from 5 to 12.

In some embodiments, the removal composition is at a temperature from20, 30 or 45 to 50, 53 or 60° C. and at a pH from 2 to 14.

In some embodiments, the removal composition is at a temperature from20, 30 or 45 to 50, 53 or 60° C. and at a pH from 5 to 12.

The removal composition has an etch rate that is stabilized up to atleast 35 hours at a selected operating temperature. In some embodiments,the selected operating temperature is from 20 to 45, 50, 53 or 60° C.

In a preferred embodiment, the concentration of ammonium carboxylate isfrom 0.001 wt % up to 50 wt %. The compositions of the invention areeffective in selectively removing an hard mask consisting essentially ofTiN, TaN, TiNxOy, TiW, W, Ti, including alloys of Ti and/or W, relativeto Low-k, Cu, Co, SiON, SICN, and TEOS materials from a semiconductorsubstrate comprising said low-k dielectric material and having a TiN,TaN, TiNxOy, TiW, W, Ti, including alloys of Ti and/or W, hard maskthereon. In addition, the composition is also functional insimultaneously removing photoresist, polymeric materials, etchingresidues and copper oxide from the substrate.

The compositions and method according to the inventive conceptsdescribed herein are particularly applicable for processing singlewafers in single wafer equipment. When a high TiN etch rate is required,a common approach is to process wafers at high process temperatures.However, higher temperatures are known to contribute to degradation ofthe oxidizing agent which shortens bath life and pot life. It has beenobserved according to the inventive concepts described herein thatsatisfactory results can be achieved at substantially lower temperaturesin the range of from 20° C. to 60° C. to generate a pullback scheme orto completely remove the hard mask when the hard mask comprises TiN.

EXAMPLES

Removal compositions according to the invention are now explained indetail by reference to the inventive concepts and examples which follow,but the present invention is not limited by these examples and theresults shown for each test. Compositions of the invention may beembodied in a wide variety of specific formulations, as hereinafter morefully described. In all such compositions, wherein specific componentsof the composition are discussed in reference to weight percentageranges including a zero lower limit, it will be understood that suchcomponents may be present or absent in various specific embodiments ofthe composition, and that in instances where such components arepresent, they may be present at concentrations as low as 0.0001 wt %,based on the total weight of the composition in which such componentsare employed.

In the examples which follow, 100 g. samples of removal compositionswere prepared according to the inventive concept(s) described herein.Each sample composition comprised each of the components listed in thevarious tables which follow at the weights shown in the correspondingformulation row. For example, a 100 g. quantity of sample compositiondesignated “1” shown in Table 1 contained 2 g. of 10% aqueous ammoniumtartrate, 7.21 g. of 10% aqueous DGA, 12.43 g. of 1.5% aqueous BTA, 60g. H2O2 (30% aqueous), and 18.36 g. deionized water (DIW).

The removal compositions can be formulated at the point of use, or theycan be conveniently formulated beforehand without an oxidizer and thentaken to the point of use where the oxidizer is added. There is also noparticular sequence for mixing or blending the various ingredients.

Blank wafers for determining etch rate were purchased as follows:

Cu blank wafer—from Silicon Valley Microelectronics, Inc.,

Co blank wafer—from Silicon Valley Microelectronics, Inc.,

TiN blank wafer—from Silyb wafer services,

W—from Silicon Valley Microelectronics, Inc.

TEOS—from Silicon Valley Microelectronics, Inc

BDII and BDIII blank wafers—from DK Nanotechnology

TiN, Cu, Co, W and TEOS Etch Rate

Etch rate evaluations were carried out after 1 and 2 minutes of chemicaltreatment for TiN and 10 minutes for Cu, Co, W, and TEOS at thetemperature noted in each example. TiN, Cu, Co, and W thicknesses weremeasured using a Four Dimensions Four Point Probe Meter 333A, wherebythe resistivity of the film was correlated to the thickness of the filmremaining after contact with the composition of the invention. The TEOSthickness was measured with Auto SE Spectroscopic Ellipsometer by HORIBAJOBIN YVON. The etch rate was calculated as the thickness change (beforeand after chemical treatment) divided by the chemical treatment time.Chemical solution pH was measured with a Beckman 260 pH/Temp/mV meter.The H₂O₂ used in the experiments was sourced from J. T. Baker. Residueremoval efficiency and TiN hard mask etch were evaluated from SEMresults (Hitachi S-5500).

The compositions shown in Table 1 were prepared using deionized water asthe solvent, BTA or a mixture of BTA and pyrazole as Cu corrosioninhibitor, H₂O₂ as the oxidizing agent, and diglycolamine (DGA) orbenzyltrimethylammonium hydroxide (BTAH) as the base to adjust pH. TiNand Cu etch rate evaluations were carried out as described above at atemperature of 50° C. and a pH of about 8.

TABLE 1 Benzyltrimeth- Ammonium ylammonium Tartrate DGA Hydroxide BTAH₂O₂ Test (10%) (10%) (40%) Pyrazole (1.5%) (30%) DIW pH TiN (Å/mm)Cu(Å/min) 1 2 7.210 0 0 12.43 60 18.36 8.4 178 (50° C.) 1.3 (50° C.) 2 33.010 0 0.5 10 70 13.49 7.6 209 (50° C.) 1.9 (50° C.) 3 3.5 0.000 2.5640.2 11.25 60 22.49 8.4 340 (53° C.) 2.5 (53° C.)Compositions 1, 2 and 3 demonstrated a removal rate for TiN in the rangeof from 178 Å/min up to 340 Å/min at a relatively low temperature in therange of from 50° C. to 53° C. A copper etch rate of less than 3 Å/minis considered good for commercial wafer processing.

Referring now to the Figs., FIGS. 1A and 1B are SEM images ofsemiconductor wafer segments which show trenches and vias, respectively,as received following a dual damascene fabrication step, but beforetreatment with a removal composition. FIGS. 2A and 2B are views of thewafer segments, similar to the wafer segments shown in FIGS. 1A and 1B,after contact with removal composition 1 for 90 sec. at a temperature of50° C. Residue was removed, but some TiN hard mask remained as noted inFIG. 2A. FIGS. 3A and 3B are views of wafer segments, similar to thewafer segments shown in FIGS. 1A and 1B, after contact with removalcomposition 2 for 90 sec. at a temperature of 50° C. wherein TiN hardmask and residue have been completely removed. FIGS. 4a and 4B are viewsof wafer segments, similar to the wafer segments shown in FIGS. 1A and1B, after contact with removal composition 3 for 90 sec. at atemperature of 53° C. TiN hard mask and residue have been completelyremoved.

The compositions shown in Table 2 were prepared using deionized water asthe solvent, BTA as Cu corrosion inhibitor, H₂O₂ as the oxidizing agent,and tetramethylammonium hydroxide (TMAH) as the base to adjust pH. TiNand Cu etch rate evaluations were carried out as described above at atemperature of 60° C. and a pH of about 7.8.

Each of the removal compositions, which contain, respectively, theammonium lactate, ammonium tartrate, ammonium carbonate, and ammoniumcitrate tribasic at the amounts indicated, demonstrated a higher TiNetch rate compared with the corresponding control, composition 4, thatdid not contain an ammonium carboxylate.

TABLE 2 Ammonium Ammonium Ammonium Ammonium Citrate Lactate TartrateCarbonate Tribasic BTA TMAH H₂O₂ TiN(Å/min) Cu(Å/min) Test (10%) (10%)(10%) (10%) (1.5%) (25%) DIW (30%) pH at 60° C. at 60° C. 4 0 0 0 0 120.816 27.18 60 7.8 215 0.98 5 1.632 0 0 0 12 0.409 25.96 60 7.8 404 1.616 0 2.807 0 0 12 0.818 24.38 60 7.8 464 1.33 7 0 0 1.46 0 12 0.305 26.2460 7.8 432 1.61 8 0 0 0 3.706 12 0.869 23.43 60 7.8 436 1.84The formulations shown in Table 3 were prepared, and TiN and Cu etchrate evaluations were carried out as described above at a temperature of50° C. and pH of 8. The removal compositions demonstrated a higher TiNetch rate and similar copper etch rate when compared to the control,composition 9, that did not contain an ammonium carboxylate.

TABLE 3 Saturated Tetrabutyl- Ammonium Ammonium Ammonium phosphoniumCarbonate Acetate Oxalate BTA Hydroxide H₂O₂ TiN(Å/min) Cu(Å/min) Test(10%) (10%) (5.5%) (1.5%) (40%) DIW (30%) pH at 50° C. at 50° C. 9 0 0 012 1.592 26.41 60 8 68 0.99 10 1.46 0 0 12 0.998 25.54 60 8 170 0.94 110 1.172 0 12 1.575 25.25 60 8 150 1.28 12 0 0 1.887 12 1.530 24.58 60 8154 1.17

The formulations shown in Table 4 were prepared using DGA to adjust thepH, and BTA was used as the copper corrosion inhibitor. TiN and Cu etchrate evaluations were carried out as described above at a temperature of50° C. and pH of 8. The removal compositions demonstrated a higher TiNetch rate and a similar Cu etch rate when compared to the control,composition 13, that did not contain an ammonium carboxylate.

TABLE 4 Saturated Ammonium Ammonium Ammonium Carbonate Acetate OxalateBTA DGA H₂O₂ TiN(Å/min) Cu(Å/min) Test (10%) (10%) (5.5%) (1.5%) (10%)DIW (30%) pH at 50° C. at 50° C. 13 0 0 0 12 2.645 25.36 60 7.9 98 0.3314 1.46 0 0 12 1.790 24.75 60 8.0 147 1.62 15 0 1.172 0 12 2.601 24.2360 8.0 146 0.2 16 0 0 1.887 12 2.502 23.61 60 7.9 140 0.83

The formulations shown in Table 5 were prepared using TMAH to adjust thepH, and BTA was used as the copper corrosion inhibitor. TiN and Cu etchrate evaluations were carried out as described above at a temperature of50° C. and pH of 8. The removal compositions demonstrated a higher TiNetch rate and a similar Cu etch rate when compared to the control,composition 17, that did not contain an ammonium carboxylate.

TABLE 5 Saturated Ammonium Ammonium Ammonium Carbonate Acetate OxalateBTA TMAH H₂O₂ TiN(Å/min) Cu(Å/min) Test (10%) (10%) (5.5%) (1.5%) (25%)DIW (30%) pH at 50° C. at 50° C. 17 0 0 0 12 0.975 27.03 60 8 99 0.12 181.46 0 0 12 0.611 25.93 60 8 200 1.85 19 0 1.172 0 12 0.866 25.96 60 8191 1.08 20 0 0 1.887 12 0.828 25.29 60 8 197 1.53

The formulations shown in Table 6 were prepared usingbenzyltrimethylammonium hydroxide (BTAH) to adjust the pH, and BTA wasused as the copper corrosion inhibitor. TiN and Cu etch rate evaluationswere carried out as described above at a temperature of 50° C. and pH ofabout 8. The removal compositions demonstrated a higher TiN etch rateand a similar Cu etch rate when compared to the control, composition 21,that did not contain an ammonium carboxylate.

TABLE 6 Saturated Benzyltrimeth- Ammonium Ammonium Ammonium ylammoniumCarbonate Acetate Oxalate BTA Hydroxide H₂O₂ TiN(Å/min) Cu(Å/min) Test(10%) (10%) (5.5%) (1.5%) (40%) DIW (30%) pH at 50° C. at 50° C. 21 0 00 12 1.127 26.87 60 8 100 0.7 22 1.46 0 0 12 0.744 25.80 60 8 178 0.6323 0 1.172 0 12 1.078 25.75 60 8 174 0.54 24 0 0 1.887 12 1.036 25.08 608 164 0.75

The formulations shown in Table 7 were prepared using tetraethylammoniumhydroxide (TEAH) to adjust the pH, and BTA was used as the coppercorrosion inhibitor. TiN and Cu etch rate evaluations were carried outas described above at a temperature of 50° C. and pH of 8. The removalcompositions demonstrated a higher TiN etch rate and a similar Cu etchrate when compared to the control, composition 25, that did not containan ammonium carboxylate.

TABLE 7 Saturated Ammonium Ammonium Ammonium Ammonium Citrate AmmoniumCarbonate Acetate Oxalate Tribasic Tartrate BTA TEAH H₂O₂ TiN(Å/min)Cu(Å/min) Test (10%) (10%) (5.5%) (10%) (10%) (1.5%) (20%) DIW (30%) pHat 50° C. at 50° C. 25 0 0 0 0 0 12 2.46 25.54 60 8 94 0.39 26 1.46 0 00 0 12 1.64 24.90 60 8 214 0.92 27 0 1.172 0 0 0 12 2.66 24.17 60 8 2180.01 28 0 0 1.887 0 0 12 2.74 23.37 60 8 197 −0.72 29 0 0 0 3.706 0 122.60 21.69 60 8 235 −0.46 30 0 0 0 0 2.807 12 2.53 22.66 60 8 209 0.03

The formulations shown in Table 8 were prepared using DGA to adjust thepH, but no copper corrosion inhibitor was used. TiN and TEOS removalrate evaluations were carried out as described above at a temperature of50° C. and pH of about 8. The removal compositions demonstrated a higherTiN etch rate when compared to the control, composition 31, that did notcontain an ammonium carboxylate.

The presence of the ammonium carbonate, ammonium acetate, ammoniumoxalate, ammonium lactate and ammonium tartrate at concentrations offrom 1.46 wt % to less than 3 wt % operate to provide the removalcompositions of the invention with the capability to deliver very highTiN etch rates at relatively low temperature, e.g., 50° C. It isnoteworthy according to the described and claimed inventive conceptsthat none of the ammonium carbonate, ammonium acetate, ammonium oxalate,ammonium lactate or ammonium tartrate had significant effect on TEOSremoval rate when compared to the control, composition 31.

TABLE 8 Saturated Ammonium Ammonium Ammonium Ammonium Ammonium CarbonateAcetate Oxalate Lactate Tartrate DGA H₂O₂ TiN(Å/min) TEOS (Å/min) Test(10%) (10%) (5.5%) (10%) (10%) (10%) DIW (30%) pH at 50° C. at 50° C. 310 0 0 0 0 2.65 37.35 60 7.93 87 0.01 32 1.46 0 0 0 0 1.52 37.02 60 7.94161 0.2 33 0 1.172 0 0 0 2.37 36.46 60 7.90 165 −0.1 34 0 0 1.887 0 02.38 35.73 60 7.90 144 0.61 35 0 0 0 1.632 0 0.94 37.43 60 7.91 181 0.4836 0 0 0 0 2.807 2.19 35.00 60 7.91 179 0.07

The formulations shown in Table 9 were prepared without the use of a pHadjustment agent. The Cu corrosion inhibitor used was Wintrol A-90, acommercial mixture of BTA and tolyltriazole. The desired TiN and Cu etchrates and pH were obtained by varying hydrogen peroxide and ammoniumcarboxylate concentrations. In these examples, several carboxylates invarious concentrations were used. Hydrogen peroxide concentration waseither 20 wt % or 80 wt %. The formulation pH's ranged from a low of pH4.3 up to pH 8.3, and the TiN etch rate, i.e., the removal rate, rangedfrom a low of 11 Å/min up to 228 Å/min.

TABLE 9 Tetra- Ammonium Ammonium Ammonium ammonium Ammonium AmmoniumCarbonate Acetate Tartrate EDTA Oxalate Lactate Wintrol H₂O₂ TiN(Å/min)Cu(Å/min) Test (10%) (10%) (10%) (10%) (10%) (10%) A-90 DIW (30%) pH at50° C. at 50° C. 37 1.46 0 0 0 0 0 0.2 78.3 20 8.3 92 0.38 38 0 0 5 0 00 0.2 74.8 20 6.0 23 2.27 39 0 0 0 10 0 0 0.2 59.8 30 8.3 116 2.19 40 01.172 0 0 0 0 0.2 78.6 20 6.2 25 0.89 41 0 0 0 0 0.35 0 0.2 79.5 20 5.111 0.13 42 0 0 0 0 0 1.632 0.2 78.2 20 7.9 73 0.11 43 1.46 0 0 0 0 0 0.218.3 80 7.1 228 1.00 44 0 1.172 0 0 0 0 0.2 18.6 80 5.5 82 0.41 45 0 0 00 0.1925 0 0.2 19.8 80 4.3 45 1.63 46 0 0 0 0 0 1.632 0.2 18.2 80 6.4173 0.60

The formulations shown in Table 10 were prepared with tartaric acid, orTMAH, or without any pH adjustment agent. Wintrol A-90 was used as a Cocorrosion inhibitor. In these examples, several carboxylates in variousconcentrations were used. Hydrogen peroxide concentration ranged from 10wt % to 80 wt %. The formulation pH ranged from a low of pH 5 up to pH10. The Co etch rate was insignificant in all cases (i.e., the highestCo etch rate was 1.48 Å/min).

TABLE 10 Ammonium Tartrate Ammonium Ammonium Tartaric dibasic LactateCarbonate Wintrol acid TEAH H₂O₂ (10%) (10%) (10%) A-90 (10%) (20%) DIW(30%) pH Co(Å/min) 47 0 1.632 0 0.2 0.585 0 37.6 60 5.00 1.48 48 2.807 00 0.2 0 0.1 36.9 60 6.50 0.21 49 0 1.632 0 0.2 0 1.9 56.3 40 8.04 −0.4850 2.807 0 0 0.2 0 6.25 80.7 10 10.00 0.51 51 0 0 1.46 0.2 0 0 18.3 807.11 −0.16 52 2.807 0 0 0.2 0 2.842 74.2 20 9.00 0.49

The results shown in Table 11 demonstrate that a mixture of ammoniumlactate and ammonium tartrate in removal composition 54 exhibited ahigher TiN etch rate when compared to the control, composition 53, whichcontained no ammonium carboxylate.

TABLE 11 Ammonium Ammonium Lactate Tartrate BTA TMAH H₂O₂ TiN(Å/min)Cu(Å/min) Co(Å/min) Test (10%) (10%) (1.5%) (25%) DIW (30%) pH at 50° C.at 50° C. at 50° C. 53 0 0 12 1.28 26.72 60 8 135 −0.1 0.3 54 0.0410.702 12 1.49 25.77 60 8 203 0.2 0.8

The formulations shown in Table 12 were prepared using TMAH to adjustthe pH, and BTA was used as copper corrosion inhibitor. Carboxylatesused were potassium citrate tribasic monohydrate, potassium sodiumtartrate tetrahydrate, and potassium L-lactate in compositions 56, 57and 58, respectively. Each of these compositions demonstrated a higherTiN etch rate and a similar Cu etch rate when compared to the control,composition 55, that did not contain a carboxylate.

TABLE 12 Potassium Potassium Citrate Sodium Tribasic Tartrate PotassiumMonohydrate Tetrahydrate L-Lactate BTA TMAH H₂O₂ TiN(Å/min) Cu(Å/min)Test (100%) (100%) (60%) (1.5%) (25%) DIW (30%) pH at 50° C. at 50° C.55 0 0 0 12 1.266 26.73 60 8.0 110 0.1 56 0.4944 0 0 12 1.194 26.31 608.0 192 1.5 57 0 0.432 0 12 1.266 26.30 60 8.0 175 −0.1 58 0 0 0.3256 121.252 26.42 60 8.0 167 0.1

The results shown in Table 13 indicate that at ammonium carboxylateconcentrations as low as 0.001%, removal compositions 60 through 63exhibited higher TiN etch rates and similar Cu and Co etch rates whencompared to the control, composition 59.

TABLE 13 Ammonium Ammonium Ammonium Ammonium Citrate Lactate TartrateCarbonate Tribasic BTA TMAH H₂O₂ TiN(Å/min) Cu(Å/min) Co(Å/min) Test(10%) (10%) (10%) (10%) (1.5%) (25%) DIW (30%) pH at 50° C. at 50° C. at50° C. 59 0 0 0 0 12 1.30 26.70 60 8 86 0.3 0.7 60 0.01 0 0 0 12 1.6926.30 60 8 93 0.2 0.6 61 0 0.01 0 0 12 1.51 26.48 60 8 107 0.0 0.6 62 00 0.01 0 12 1.53 26.46 60 8 119 0.4 0.6 63 0 0 0 0.01 12 1.37 26.62 60 8102 0.1 0.4

The results shown in Table 14 demonstrate that at an ammonium acetateconcentration of 50 wt %, removal composition 65 exhibited a higher TiNetch rate and similar Cu and Co etch rates when compared to the control,composition 64, which contained no ammonium carboxylate.

TABLE 14 Ammonium Acetate BTA DGA H₂O₂ TiN(Å/min) Cu(Å/min) Co(Å/min)Test (100%) (1.5%) (10%) DIW (30%) pH at 30° C. at 30° C. at 30° C. 64 012 1.060 56.94 30 7.8 8 0.3 0.1 65 50 12 4.450 3.55 30 7.8 18 1.6 0.3Tungsten (W) Etch RateThe formulations shown in Table 15 were prepared, and W (tungsten) etchrate evaluations were carried out at temperatures of 45° C. and 55° C.as described above in connection with TiN removal.

TABLE 15 Saturated Ammonium Ammonium Ammonium Ammonium TartaricCarbonate Acetate Oxalate Tartrate DGA TMAH Acid H₂O₂ W (Å/min) Test(10%) (10%) (5.5%) (10%) (10%) (25%) (10%) DIW (30%) pH at 45° C. 66 0 00 0 2.645 0 0.00 37.4 60 7.9 173 67 1.46 0 0 0 1.790 0 0.00 36.8 60 8.0401 68 0 1.172 0 0 2.601 0 0.00 36.2 60 8.0 444 69 0 0 1.887 0 2.502 00.00 35.6 60 7.9 361 70 0 0 0 0 0.000 19.517 0.00 20.5 60 11.1 365 71 00 0 3 0.000 20.272 0.00 16.7 60 11.1 771 72 0 0 0 0 0.000 0 0.42 40.0 603.9  751 (55° C.) 73 0 0 0 3 0.000 0 0.48 36.5 60 3.9 1046 (55° C.)

Table 15 demonstrates the presence of ammonium carboxylate at aconcentration of 1.172 wt % to 3 wt % and at a pH ranging from about 4to slightly higher than 11 was shown to significantly increase the Wremoval rate when compared to the corresponding ammoniumcarboxylate-free control compositions 66, 70 and 72 at the same pH.

Removal Composition Stability

Pot life is a measure of the ability of the removal composition formulato perform optimally over time and without significant variation infunctionality over time. Pot life is a strong function of temperature.After many hours of treatment at high temperature, the chemicals in themixture can decompose and the formula will lose functionality. Pot lifestudies were conducted (to confirm the period of time during which, andthe extent to which, the etch rates of the removal compositions of theinvention remained constant) as follows: 1200 gram stock solutions wereprepared and maintained at 50° C. 150 gram samples were removed from theheated stock solution and used for TiN and Cu etch rate and pH studiesat specific times at 50° C. The samples were discarded after each etchrate measurement.

Removal compositions were prepared according to the described andclaimed inventive concept(s) wherein ammonium tartrate was selected asthe ammonium carboxylate at a concentration of 0.3 wt %.1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA) was selected asthe aminopolycarboxylic acid chelating agent in formulation 74, 75, andno chelating agent (CDTA) was included in the control formulation 76.The compositions are shown in Table 16. Results are shown in Table 17.

TABLE 16 Ammonium Tartrate CDTA TEAH BTA H₂O₂ Test (10%) Pyrazole (100%)(20%) (1.5%) DIW (30%) pH 74 3 0.3 0.200 3.122 12.120 21.258 60 8.07 753 0.3 0.607 5.482 12.120 18.491 60 8.05 76 3 0.3 0.000 2.220 12.12022.36 60 8.15

TABLE 17 TiN (Å/min) Cu (Å/min) Test Time (hr) at 50° C. at 50° C. 74 0168.1 0.12 75 157.0 0.03 76 219.0 −0.02 74 2 166.0 0.53 75 143.7 0.46 76211.2 0.45 74 4 163.7 1.42 75 155.5 0.90 76 203.6 0.62 74 7.5 159.4 0.7775 157.4 1.11 76 166.6 −0.02 74 22 156.6 0.53 75 156.4 1.47 76 99.9 0.52

The data presented in Table 17 demonstrates that with CDTA in removalcompositions 74 and 75, the TiN etch rate remained stable, i.e.,substantially constant, over a period of 22 hours. The initial TiN etchrate was 157 Å/min, and it remained at 156.4 Å/min for composition 75over a 22 hour period. For composition 74 the initial TiN etch rate was168.1 Å/min and remained at 156.6 Å/min over a 22 hour period. Incomposition 76, without CDTA, the TiN etch rate declined from an initialetch rate of 219 Å/min to an etch rate of 99.9 Å/min at 22 hours.

TABLE 18 Ammonium Tartrate CDTA TEAH BTA H₂O₂ Test (10%) Pyrazole (100%)(20%) (1.5%) DIW (30%) pH 77 2.5 0.300 0.500 5.108 12.0 19.59 60 7.9 782.5 0.300 0.000 2.210 12.0 22.99 60 7.9

TABLE 19 TiN (Å/min) Cu (Å/min) Test Time (hr) at 50° C. at 50° C. 77 0174 2.20 78 212 1.59 77 4 178 1.49 78 194 0.83 77 8 170 1.70 78 180 1.4977 24 171 1.77 78 150 1.24 77 28 163 1.25 78 118 0.59 77 32 159 0.93 78109 0.58 77 35 160 1.07 78 110 0.88

The data presented in Table 19 demonstrates that with CDTA in removalcompositions 77, the TiN etch rate remained stable, i.e., substantiallyconstant, over a period of 35 hour. The initial TiN etch rate was 174Å/min, and it is at 160 Å/min for composition 77 at 35 hour period. Incomposition 78 without CDTA, the TiN etch rate declined from an initialetch rate of 212 Å/min to an etch rate of 110 Å/min at 35 hours.

Removal compositions were prepared according to the described andclaimed inventive concept(s) wherein Tetraammoniumethylenediaminetetraacetic acid, Triammonium ethylenediaminetetraaceticacid and Diammonium ethylenediaminetetraacetic acid was selected as theammonium carboxylate at a concentration of specified in Table 20.1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA) was selected asthe aminopolycarboxylic acid chelating agent in formulation 79, 80 and81. The compositions are shown in Table 20.

Samples were taken from the removal compositions at intervals of 0, 4,8, 24, 28, 32 and 35 hours to measure TiN and Cu etch rates. Results areshown in Table 21.

TABLE 20 Tetra- Tri- Di- ammonium ammonium ammonium EDTA EDTA EDTA TEAHBTA CDTA H₂O₂ Test (10%) (10%) (10%) (20%) (1.5%) (100%) DIW (30%) pH 793.25 0 0 4.781 12 0.5 19.47 60 7.9 80 0 3.1928 0 5.470 12 0.5 18.84 607.9 81 0 0 3.035 5.888 12 0.5 18.58 60 7.9

TABLE 21 TiN (Å/min) at Cu (Å/min) Test Time (hr) 50° C. at 50° C. 79 0192 2.24 80 181 1.73 81 167 1.27 79 4 184 2.59 80 182 1.76 81 160 1.8279 8 190 1.85 80 182 2.26 81 166 1.36 79 24 169 1.33 80 161 1.27 81 1561.99 79 28 174 0.66 80 164 0.22 81 157 1.61 79 32 173 1.68 80 167 1.5981 154 1.46 79 35 176 1.65 80 171 1.23 81 160 1.60

The data presented in Table 21 demonstrates that with CDTA in removalcompositions 79, 80 and 81, the TiN etch rate remained stable, i.e.,substantially constant, over a period of 35 hours. The initial TiN etchrate was 192 Å/min, and it is at 176 Å/min for composition 79 over a 35hour period. For composition 80, the initial TiN etch rate was 181 Å/minand is at 171 Å/min over a 35 hour period. For composition 81 theinitial TiN etch rate was 167 Å/min and is at 160 Å/min over a 35 hourperiod.

Removal compositions were prepared according to the described andclaimed inventive concept(s) wherein ammonium tartrate was selected asthe ammonium carboxylate at a concentration of 0.3 wt %.1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA) was selected asthe aminopolycarboxylic acid chelating agent in formulation 82 and 83.The compositions are shown in Table 22. Samples were taken from theremoval compositions at intervals of 0, 4, 8, 24, 28, 32 and 35 hours tomeasure TiN and Cu etch rates. Results are shown in Table 23.

TABLE 22 (NH4)2 Tartrate dibasic Pyr- TEAH BTA CDTA H₂O₂ Test (10%)azole (20%) (1.5%) (100%) DIW (30%) pH 82 3 0.3 0.404 12.12 0.001 74.1810 8.0 83 3 0.3 0.632 12.12 0.005 73.94 10 8.2 84 3 0.3 0.387 12.12 074.19 10 8.0

TABLE 23 Time TiN (Å/min) Cu (Å/min) Test (hr) at 50° C. at 50° C. 82 042 −0.13 83 48 0.21 84 47 0.04 82 4 41 0.13 83 49 −0.17 84 41 0.09 82 840 0.53 83 47 0.88 84 37 1.20 82 24 40 0.39 83 47 −0.38 84 33 0.59 82 2838 0.54 83 46 0.43 84 32 0.81 82 32 38 0.44 83 46 0.88 84 30 1.08 82 3536 0.23 83 45 1.22 84 30 1.21

The data presented in Table 23 demonstrates that with 0.001% and 0.005%of CDTA in removal compositions 82 and 83, respectively, the TiN etchrate remained stable, i.e., substantially constant, over a period of 35hours. The initial TiN etch rate was 42 Å/min, and it remained at 36Å/min for composition 82 over a 35 hour period (16.67% reduced TiN etchrate). For composition 83, the initial TiN etch rate was 48 Å/min andremained at 45 Å/min over a 35 hour period (6.3% reduced TiN etch rate).For comparison, control formulation 84 without CDTA, the initial TiNetch rate was 47 Å/min, and it is at 30 Å/min for over a 35 hour periodwhich shows a 36% reduced TiN etch rate. CDTA stabilizes TiN etch rate.

The formulations shown in Table 24 were prepared using TEAH to adjustthe pH, and BTA was used as copper corrosion inhibitor. CDTA was used tostabilize TiN etch rate.

A pot life study of Table 24 formulations were conducted according tothe method described above. Samples were taken at intervals of 0, 4, 8,24, 28, 32 and 35 hours to measure TiN and Cu etch rates and pH. Resultsare shown in Table 25.

TABLE 24 (NH4)2 Tartrate dibasic TEAH BTA CDTA H₂O₂ Test (10%) (20%)(1.5%) (100%) DIW (30%) pH 85 2.5 18.910 12 3 3.59 60 7.84 86 2.5 13.18912 2 10.31 60 7.84 87 2.5 7.518 12 1 16.98 60 7.84 88 2.5 1.974 12 023.53 60 7.84

TABLE 25 Time TiN (Å/min) Cu (Å/min) Test (hr) at 50° C. at 50° C. 85 0170 1.79 86 170 1.96 87 178 1.84 88 233 1.78 85 4 167 1.68 86 170 0.3387 173 0.57 88 196 1.21 85 8 165 1.75 86 167 1.81 87 171 0.78 88 1900.64 85 24 156 1.70 86 160 1.71 87 168 1.78 88 151 1.01 85 28 153 2.5186 156 2.39 87 168 1.21 88 144 0.96 85 32 151 2.74 86 155 2.56 87 1661.75 88 137 1.32 85 35 159 2.90 86 158 2.41 87 166 1.84 88 136 0.82

The data presented in Table 25 demonstrate that with 1%, 2% and 3% CDTAin removal compositions 85, 86 and 87, respectively, the TiN etch rateremained stable, i.e., substantially constant, over a period of 35hours. The initial TiN etch rate was 170 Å/min, and it remained at 159Å/min for composition 85 at a 35 hour period. For composition 86, theinitial TiN etch rate was 170 Å/min and remained at 158 Å/min at 35 hourperiod. For composition 87, the initial TiN etch rate was 178 Å/min andremained at 166 Å/min at 35 hour period. For comparison, controlformulation 88 without CDTA, the initial TiN etch rate was 233 Å/min,and it is at 136 Å/min for over a 35 hour period. CDTA stabilizes TiNetch rate.

The formulations shown in Table 26 were prepared using DGA to adjust thepH, and BTA was used as copper corrosion inhibitor. Tetraammoniumethylenediaminetetraacetic acid was used to stabilize the TiN etch rate.

A pot life study of Table 26 formulations were conducted according tothe method described above. Samples were taken at intervals of 0, 2, 4,8, 24, 28 and 35 hours to measure TiN and Cu etch rates and pH. Resultsare shown in Table 27.

TABLE 26 Tetra- ammonium EDTA DGA BTA H₂O₂ Test (10%) Pyrazole (10%)(1.5%) DIW (30%) pH 89 6.0 0.300 1.740 12.12 19.84 60 7.9 90 0.0 0.3003.360 12.12 24.22 60 7.9

TABLE 27 TiN (Å/min) Cu (Å/min) Test Time (hr) at 50° C. at 50° C. 89 0224 2.07 90 143 0.90 89 2 223 1.15 90 127 0.47 89 4 225 1.96 90 112 1.4489 8 219 0.88 90 96 0.28 89 24 192 0.96 90 75 0.78 89 28 190 1.36 90 640.55 89 35 179 0.73 90 57 0.36

Table 27 demonstrates that with tetraammoniumethylenediaminetetraacetate in removal composition 89, the TiN etch rateremained stable, i.e., remained substantially constant, over a period ofthirty five (35) hours. The initial TiN etch rate was 224 Å/min, and itis at 179 Å/min at thirty five (35) hour (20% TiN etch rate drop after35 hours). In composition 90, without Tetraammoniumethylenediaminetetraacetate, the etch rate dropped from an initial rateof 143 Å/min to a rate of 57 Å/min after 35 hours (60% TiN etch ratedrop after 35 hours). Tetraammonium ethylenediaminetetraacetatestabilizes TiN etch rate.

The formulations in Table 28 were prepared using DGA to adjust pH. BTAwas used as copper corrosion inhibitor. The ammonium carboxylateselected was tetraammonium EDTA. The results shown in Table 28 indicatethat Tetraammonium ethylenediaminetetraacetate in removal composition 81exhibited a higher TiN etch rate when compared to the control,composition 82, which contained no ammonium carboxylate.

TABLE 28 Tetra- ammonium DGA EDTA BTA H₂O₂ TiN(Å/min) Cu(Å/min) TestPyrazole (10%) (10%) (1.5%) DIW (30%) at 50° C. at 50° C. pH 91 0.31.740 6.0 12.12 19.84 60 233 1.97 7.9 92 0.3 3.360 0.0 12.12 24.22 60134 0.18 7.9

TABLE 29 Time TiN (Å/min) Cu (Å/min) Test (hr) at 50° C. at 50° C. 91 0233 2.07 92 134 0.90 91 2 232 1.15 92 119 0.47 91 4 234 1.96 92 105 1.4491 8 228 0.88 92 90 0.28 91 24 200 0.96 92 71 0.78 91 28 198 1.36 92 610.55

The experimental results shown in Table 29 demonstrate that withtetraammonium ethylenediaminetetraacetate in removal composition 81, theinitial TiN etch rate was 233 Å/min, and it is 198 Å/min at twenty eight(28) hour period. In composition 92, without Tetraammoniumethylenediaminetetraacetate, the TiN etch rate dropped from an initialrate of 134 Å/min to a rate of 61 Å/min at 28 hours.

The presence of ammonium carboxylate in the removal compositions of theinvention not only increased TiN etch rate as shown in Tables 2 through8, 11, 13 through 15, and 26 and 27, but the data support the conclusionthat their presence also operates to stabilize the TiN etch rate over anextended period of time, e.g., up to at least 35 hours.

Several embodiments of the inventive concepts have been described.However, those ordinarily skilled in the art will recognize that theinvention is not limited to the embodiments described. The inventiveconcepts can be practiced with modifications and alteration within thespirit and scope of the appended claims.

What is claimed is:
 1. A removal composition for selectively removing ahard mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti andalloys of Ti and W relative to low-k dielectric material from asemiconductor substrate which comprises the low-k dielectric materialhaving a TiN, TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard maskthereon, the removal composition comprising: (a) 0.1 wt % to 90 wt % ofan oxidizing agent; (b) 0.0001 wt % to 50 wt % of a carboxylate; (c)0.0001 wt % up to 50 wt % of a metal corrosion inhibitor; and (d) thebalance up to 100 wt % of the removal composition comprising deionizedwater; wherein said metal corrosion inhibitor is one or more membersselected from the group consisting of pyrrole and derivatives thereof,pyrazole and derivatives thereof, and indazole and derivatives thereof,and wherein said composition does not contain hydrofluoric acid.
 2. Theremoval composition of claim 1, wherein the oxidizing agent is selectedfrom the group consisting of hydrogen peroxide (H2O2),n-methylmorpholine oxide (NMMO or NMO), benzoyl peroxide,tetrabutylammonium peroxymonosulfate, ozone, ferric chloride,permanganate peroxoborate, perchlorate, persulfate, ammoniumperoxydisulfate, urea hydroperoxide, nitric acid (HNO3), ammoniumchlorite (NH4ClO2), ammonium chlorate (NH4ClO3), ammonium iodate(NH4IO3), ammonium perborate (NH4BO3), ammonium perchlorate (NH4ClO4),ammonium periodate (NH4IO3), ammonium persulfate ((NH4)25208),tetramethylammonium chlorite ((N(CH3)4)ClO2), tetramethylammioniumchlorate ((N(CH3)4)ClO3), tetramethylammonium iodate ((N(CH3)4)IO3),tetramethylammonium perborate ((N(CH3)4)BO3), tetramethylammoniumperchlorate ((N(CH3)4)ClO4), tetramethylammonium periodate((N(CH3)4)IO4), tetramethylammonium persulfate ((N(CH3)4)S2O8),((CO(NH2)2)H2O2), peracetic acid (CH3(CO)OOH), and mixtures thereof; andthe carboxylate is selected from the group consisting of potassiumcitrate tribasic monohydrate, potassium sodium tartrate tetrahydrate,potassium L-Lactate and mixtures thereof.
 3. The removal composition ofclaim 2 further comprising: 0.001 wt % to 20 wt % of an amino acid, anaminopolycarboxylic acid, a carboxylic acid, a polycarboxylic acid, or amixture thereof selected from the group consisting of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);and ethylenediamine-N, N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid; and triethylenetetraaminehexaacetic acid (TTNA).
 4. The removal composition of claim 1, whereinthe metal corrosion inhibitor further comprising benzotriazole ortolyltriazole.
 5. The removal composition of claim 2 further comprising:at least one base, at least one acid or mixture thereof; wherein thebase is selected from the group consisting of quaternary ammonium salts,primary amines, secondary amines, tertiary amines, tetramethylammoniumhydroxide (TMAH), tetraethylammonium hydroxide (TEAH),benzyltrimethylammonium hydroxide (BTAH), monoethanol amine (MEA),diglycol amine (DGA), triethanolamine (TEA), tetrabutyphosphoniumhydroxide (TBPH), and mixtures thereof; and wherein the acid is selectedfrom the group consisting of inorganic acids, a carboxylic acid, anamino acid, a hydroxy carboxylic acid, a polycarboxylic acid, and amixture thereof.
 6. The removal composition of claim 2 furthercomprising: i) 0.001 wt % to 20 wt % of an amino acid, anaminopolycarboxylic acid, a carboxylic acid, a polycarboxylic acid, or amixture thereof selected from the group consisting of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);and ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid; and triethylenetetraaminehexaacetic acid (TTHA).
 7. The removal composition of claim 2 furthercomprising: i) 0.001 wt % to 20 wt % of an amino acid, anaminopolycarboxylic acid, a carboxylic acid, a polycarboxylic acid, or amixture thereof selected from the group consisting of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);and ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid; and triethylenetetraaminehexaacetic acid (TTHA); and ii) at least one base, at least one acid ormixture thereof; wherein the base is selected from the group consistingof quaternary ammonium salts, primary amines, secondary amines, tertiaryamines, tetramethylammonium hydroxide (TMAH), tetraethylammoniumhydroxide (TEAH), benzyltrimethylammonium hydroxide (BTAH), monoethanolamine (MEA), diglycol amine (DGA), triethanolamine (TEA),tetrabutyphosphonium hydroxide (TBPH), and mixtures thereof; and whereinthe acid is selected from the group consisting of inorganic acids, acarboxylic acid, an amino acid, a hydroxy carboxylic acid, apolycarboxylic acid, and a mixture thereof.
 8. The removal compositionof claim 1, wherein the carboxylate is an ammonium carboxylate.
 9. Theremoval composition of claim 8, wherein the oxidizing agent is selectedfrom the group consisting of hydrogen peroxide (H2O2),n-methylmorpholine oxide (NMMO or NMO), benzoyl peroxide,tetrabutylammonium peroxymonosulfate, ozone, ferric chloride,permanganate peroxoborate, perchlorate, persulfate, ammoniumperoxydisulfate, per acetic acid, urea hydroperoxide, nitric acid(HNO3), ammonium chlorite (NH4ClO2), ammonium chlorate (NH4ClO3),ammonium iodate (NH4IO3), ammonium perborate (NH4BO3), ammoniumperchlorate (NH4ClO4), ammonium periodate (NH4IO3), ammonium persulfate((NH4)2S2O8), tetramethylammonium chlorite ((N(CH3)4)ClO2),tetramethylammionium chlorate ((N(CH3)4)ClO3), tetramethylammoniumiodate ((N(CH3)4)IO3), tetramethylammonium perborate ((N(CH3)4)BO3),tetramethylammonium perchlorate ((N(CH3)4)ClO4), tetramethylammoniumperiodate ((N(CH3)4)IO4), tetramethylammonium persulfate((N(CH3)4)S2O8), ((CO(NH2)2)H2O2), peracetic acid (CH3(CO)OOH), andmixtures thereof; and the ammonium carboxylate is selected from thegroup consisting of ammonium oxalate, ammonium lactate, ammoniumtartrate, ammonium citrate tribasic, ammonium acetate, ammoniumcarbamate, ammonium carbonate, ammonium benzoate, ammoniumethylenediaminetetraacetic acid, diammonium ethylenediaminetetraaceticacid, triammonium ethylenediaminetetraacetic acid, tetraammoniumethylenediaminetetraacetic acid, ammonium succinate, ammonium formate,ammonium 1-H-pyrazole-3-carboxylate and mixtures thereof.
 10. Theremoval composition of claim 9, further comprising from 0.001 wt % to 20wt % of an amino acid, an aminopolycarboxylic acid, a carboxylic acid, apolycarboxylic acid, or a mixture thereof selected from the groupconsisting of 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);and ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid; and triethylenetetraaminehexaacetic acid (TTNA).
 11. The removal composition of claim 9, whereinthe metal corrosion inhibitor further comprising benzotriazole ortolyltriazole.
 12. The removal composition of claim 9 furthercomprising: at least one base, at least one acid or mixture thereof;wherein the base is selected from the group consisting of quaternaryammonium salts, primary amines, secondary amines, tertiary amines,tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide(TEAH), benzyltrimethylammonium hydroxide (BTAH), monoethanol amine(MEA), diglycol amine (DGA), triethanolamine (TEA), tetrabutyphosphoniumhydroxide (TBPH), and mixtures thereof; and wherein the acid is selectedfrom the group consisting of inorganic acids, a carboxylic acid, anamino acid, a hydroxy carboxylic acid, a polycarboxylic acid, and amixture thereof.
 13. The removal composition of claim 9 furthercomprising: 0.001 wt % to 20 wt % of an amino acid, anaminopolycarboxylic acid, a carboxylic acid, a polycarboxylic acid, or amixture thereof selected from the group consisting of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);and ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid; and triethylenetetraaminehexaacetic acid (TTHA).
 14. The removal composition of claim 9 furthercomprising: i) 0.001 wt % to 20 wt % of an amino acid, anaminopolycarboxylic acid, a carboxylic acid, a polycarboxylic acid, or amixture thereof selected from the group consisting of1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid;ethylenediaminetetraacetic acid; nitrilotriacetic acid; diethylenetriamine pentaacetic acid;1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; ethyleneglycol tetraacetic acid (EGTA);1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid;N-{2-[bis(carboxymethyl)amino]ethyl}-N-(2-hydroxyethyl)glycine (HEDTA);and ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA);dioxaoctamethylene dinitrilo tetraacetic acid; and triethylenetetraaminehexaacetic acid (TTHA); and ii) at least one base, at least one acid ormixture thereof; wherein the base is selected from the group consistingof quaternary ammonium salts, primary amines, secondary amines, tertiaryamines, tetramethylammonium hydroxide (TMAH), tetraethylammoniumhydroxide (TEAH), benzyltrimethylammonium hydroxide (BTAH), monoethanolamine (MEA), diglycol amine (DGA), triethanolamine (TEA),tetrabutyphosphonium hydroxide (TBPH), and mixtures thereof; and whereinthe acid is selected from the group consisting of inorganic acids, acarboxylic acid, an amino acid, a hydroxy carboxylic acid, apolycarboxylic acid, and a mixture thereof.
 15. The removal compositionof claim 9 further comprising: 0.001 wt % to 20 wt %1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid.
 16. The removalcomposition of claim 15, wherein the ammonium carboxylate is selectedfrom ammonium tartrate.
 17. The removal composition of claim 9, whereinthe ammonium carboxylate is selected from the group consisting ofammonium ethylenediaminetetraacetic acid, diammoniumethylenediaminetetraacetic acid, triammonium ethylenediaminetetraaceticacid, tetraammonium ethylenediaminetetraacetic acid and mixturesthereof.
 18. The removal composition of claim 1, wherein the pH is from5 to
 11. 19. The removal composition of claim 1, wherein the pH is from7.6 to
 11. 20. A removal composition for selectively removing a hardmask consisting essentially of TiN, TaN, TiNxOy, TiW, W, Ti and alloysof Ti and W relative to low-k dielectric material from a semiconductorsubstrate which comprises the low-k dielectric material having a TiN,TaN, TiNxOy, TiW, W, Ti or alloy of Ti or W hard mask thereon, theremoval composition comprising: (a) 0.1 wt % to 90 wt % of an oxidizingagent; (b) 0.0001 wt % to 50 wt % of a carboxylate; (c) 0.0001 wt % upto 50 wt % of a metal corrosion inhibitor; and (d) the balance up to 100wt % of the removal composition comprising deionized water; wherein saidmetal corrosion inhibitor is one or more members selected from the groupconsisting of pyrazole and derivatives thereof, and indazole andderivatives thereof.